In this paper, crystal plasticity model, in combination with XFEM, has been applied to study cyclic deformation and fatigue crack growth in a nickel-based superalloy LSHR (Low Solvus High Refractory) at high temperature. The first objective of this research was to develop and evaluate a RVE-based finite element model with the incorporation of a realistic material microstructure. The second objective of this work was to determine the parameters of a crystal plasticity constitutive model to describe the cyclic deformation behaviour of the material by using a user-defined material subroutine (UMAT) interfaced with the finite element package ABAQUS. The model parameters were calibrated from extensive finite element analyses to fit the monotonic, stress relaxation and cyclic test data. The third objective was to predict crack growth by combining the XFEM technique and the calibrated crystal plasticity UMAT, for which accumulated plastic strain was used as the fracture criterion.
